The invention relates to a method and apparatus for the production of a synthetic filament yarn and which includes advancing a freshly spun yarn through an elongate heating chamber.
DE-A 38 08 854 discloses a yarn heating process wherein a freshly spun synthetic filament yarn is advanced at a high speed through a heating tube while it is being drawn. To obtain high speeds, it is also necessary to apply high temperatures.
It is the object of the present invention to prevent or lessen chemophysical reactions of the yarn material in the thermal treatment of an advancing synthetic filament yarn, which may for example consist of polyester, polyamide, nylon, and polypropylene filaments. It is intended to prevent such reactions, which result in an increased amount of contamination in the heater and on the yarn, as well as on subsequent yarn guide elements, in discoloration of the yarn material, shrinkage, or other disadvantageous consequences, or which adversely affect the capacity of the yarn to absorb spin finishes, adhesives, and dyes that are applied.